1. Field of the Invention.
This invention relates to the field of winches. More specifically the present invention comprises a winch drum drive system for selectively operating multiple winch drums.
2. Description of the Related Art
Although winch drum drive systems have utilities in many fields, winch drum drive systems are particularly useful in the field of kite sailing where kites are used to power watercraft. Kite sailing involves the use of traction kites to harness wind energy for propulsion power. The towing kite is held within a stream of moving air, creating a pressure differential that causes the vessel to move.
Kites provide several unique advantages over traditional sails. One advantage is increased stability. Traditional sail boats experience a heeling moment which causes the vessel to tilt. When equipped with a traction kite, the force a ship experience has an upward and lateral component. The upward component, called the lifting force, generates a righting moment. This moment counteracts the heeling moment cause by the lateral component of the force, thereby providing a higher degree of stability. Traction kites also offer an advantage of increased speed. Kites can be raised to higher altitudes than traditional sails. Under most conditions, the wind speed increases with increasing altitude. Accordingly, kites can be used to harness wind energy at various altitudes to achieve optimum speeds.
Although the use of kites to power watercraft is a well-known idea, several limitations have prevented widespread acceptance. Control of a kite requires the use of multiple control lines. For small recreational watercraft, a single user can typically manage the control of the kite manually. Larger watercraft require larger kites, and larger kites can be complex to control. One reason for this is that bigger kites supply more tension on the control lines. It is therefore desirable to provide a control system suitable for controlling large kites with multiple control lines. The winch described herein was developed to provide this control; however, the reader should understand that the winch described herein has many other applications.